The mission of the United States is to provide global leadership grounded in the understanding that the world shares a common security and a common humanity. The American moment is not over, but it must be seized anew. To see American power in terminal decline is to ignore America’s great promise and historic purpose in the world. If elected president, I will start renewing that promise and purpose the day I take office. — Barack Obama, “Renewing American Leadership”, Foreign Affairs 86:4, 4